JPH10340138A - Electronic device - Google Patents

Abstract

(57) [Problem] To provide an electronic device capable of improving the heat radiation effect when a cooling fan is used and capable of being designed to be thin. SOLUTION: A heat sink A6 on which a cooling fan 5 is mounted and a heat sink B8 are mounted on a sub-circuit board 2 on which the CPU package 3 is mounted via a thermally conductive aluminum block 10 and a silicon sheet 9.
Attach so that it comes into close contact from both sides.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic device having a built-in heat-generating component, such as a CPU, which becomes hot when used, and more particularly, to an electronic device having an air cooling structure for lowering the temperature.

[0002]

2. Description of the Related Art Conventionally, in an electronic device having a built-in heat-generating component such as a CPU of a word processor or a portable computer which becomes high in temperature when used, it is necessary to lower the temperature in order to prevent the heat generation from affecting the performance. Have been devised in various ways.

[0003] As a conventional heat dissipating structure for a heat-generating component, a structure as shown in FIG. 2 is known. FIG. 2 is a partial cross-sectional view showing a heat dissipation structure used in a conventional portable computer. In the figure, 21 is a CPU package as a heat-generating component, 22 is a circuit board on which the CPU package 21 is mounted, 23 is a heat sink attached in close contact with the upper surface of the CPU package 21, 24 is a cooling fan further attached to the heat sink 23, Reference numeral 25 denotes an exhaust hole provided in the housing of the portable computer.

[0004] The heat dissipation operation of the portable computer having the heat dissipation structure configured as described above will be described below.

The heat generated from the CPU package 21 is transmitted to the heat sink 23 and is radiated. However, when the cooling fan 24 rotates, the inhaled air deprives the heat sink 23 of the heat and transfers the heat in the direction of the arrow. Forcibly diverge. This heat is further radiated out of the housing of the portable computer through the exhaust hole 25.

As a result, the CPU package 21 is cooled, and the influence on the performance can be reduced.

[0007]

Recently, with the improvement of the performance of CPUs and the like, the conventional heat radiating structure of a portable computer selects a fan having a large cooling fan capacity in order to enhance the cooling effect. In such a case, noise and power consumption increase. In addition, the size of the cooling fan increases, which goes against a portable computer that aims to be lightweight and thin.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an electronic device which can enhance the heat radiation effect when a cooling fan is used and can be designed to be thin.

[0009]

SUMMARY OF THE INVENTION In order to solve this problem, the present invention mounts a heat-generating component on a sub-circuit board separated from a main circuit board, attaches heat sinks to the front and back surfaces of the heat-generating component, and further cools down. It is configured to radiate heat by a fan.

[0010] Thus, the cooling effect of the cooling fan is enhanced, and the thickness of the device housing is easily reduced.

[0011]

DETAILED DESCRIPTION OF THE INVENTION The invention according to claim 1 of the present invention is directed to a main circuit board on which electronic components are mounted, and an electronic component (hereinafter, referred to as a heat-generating component) separated from the main circuit board and subjected to heat radiation. An electronic device comprising: a sub-circuit board on which a heat-generating component is mounted; a cooling fan for cooling the heat-generating component; and a heat sink to which the cooling fan is attached. In addition to enhancing the cooling effect, it has an effect that a thin case design can be made because the degree of freedom is increased in a mounting place.

According to a second aspect of the present invention, there is provided a cooling fan for cooling a heat-generating component, a first heat sink to which the cooling fan is mounted, and a close contact with the heat-generating component directly or via a heat conductive material. A second heat sink, a circuit board on which the heat-generating component is mounted, and a circuit board having an opening at a portion where the heat-generating component is mounted, and interposed between the heat-generating component and the first heat sink through the hole. An electronic device including a heat conductive block, which cools a heat-generating component from both front and rear surfaces, and thus has an effect of increasing a cooling effect even when a cooling fan has the same capacity.

According to a third aspect of the present invention, there is provided a main circuit board on which an electronic component is mounted, a sub-circuit board separated from the main circuit board and having a heat-generating component mounted thereon, and a cooling device for cooling the heat-generating component. A fan, a first heat sink to which the cooling fan is attached, a second heat sink that is in direct contact with the heat-generating component or through a heat conductive material, and a mounting portion where the heat-generating component is mounted and the heat-generating component is mounted. An electronic apparatus comprising: a circuit board having an opening; and a heat conductive metal interposed between the heat-generating component and the first heat sink through the opening.
This has the effect of enhancing the cooling effect of the cooling fan and enabling the design of a thin housing.

An embodiment of the present invention will be described below with reference to the drawings. (Embodiment 1) FIG. 1 is a partial cross-sectional view showing a heat dissipation structure of a portable computer which is an electronic apparatus of the present invention, wherein 1 is a main circuit board, and 2 is a sub-circuit on which a CPU package 3 which is a heat generating component is mounted. The board is electrically connected to the main circuit board 1 by a connector 4. The sub-circuit board 2 is composed of only the CPU package 3 or a minimum of electronic components constituting peripheral circuits. 5 is a cooling fan, 6 is a cooling fan 5
Is attached to the main circuit board with a screw (not shown) by a heat sink A to which is attached. Reference numeral 8 denotes a heat sink B, which is attached to a heat sink A6 with screws 7. The heat sink A6 and the heat sink B8 are formed of a heat conductive metal material such as aluminum. The heat sink B8 is
It is in close contact with the CPU package 3 via a thermally conductive silicon sheet 9. An opening 2a is provided in the mounting position of the CPU package 3 on the sub-circuit board 2, and an aluminum block 10 made of a heat conductive metal material is provided between the mounting surface of the CPU package 3 and the heat sink A6 through the opening 2a. Is sandwiched between. The aluminum block 10 is in close contact with the heat sink A6 by thermal conductive grease, and is in close contact with the CPU package 3 by an adhesive. Reference numeral 11 denotes an exhaust hole provided in the housing of the portable computer.

The heat radiating operation of the portable computer having the heat radiating structure of the present invention configured as described above will be described. First, heat is radiated from the heat-generating CPU package 3 through the silicon sheet 9 and from the heat sink B8.
Heat is radiated from the heat sink A6 through the aluminum block 10. As the cooling fan 5 rotates, the sucked air deprives the heat of the heat sink A6 and forcibly diverges in the direction of the arrow. Further, this heat is radiated from the exhaust port 11 to the outside of the housing of the portable computer.

Thus, since the CPU package 3 is cooled from both sides, the heat radiation effect can be greatly improved.

Further, since the sub-circuit board 2 on which the CPU package 3 is mounted is separated from the main circuit board 1, the mounting position of the cooling fan can be freely set, and the thin design of the housing of the portable computer becomes easy.

Further, when the CPU package 3 is replaced for the purpose of improving performance, the replacement is easy because the sub-circuit board 2 is separated from the main circuit board 1.

If the heat sink A6 to which the cooling fan 5 is attached is removed from the main circuit board 1, the cooling fan can be replaced at the same time when the CPU is replaced.

In this embodiment, the heat sink A
Although the heatsink 6 and the heatsink B8 are formed separately, it goes without saying that they may be integrated.

In place of the silicon sheet 9 which is in close contact between the CPU package 3 and the heat sink B8, any material such as silicon grease or adhesive may be used as long as it has good heat conductivity.

[0022]

As described above, according to the present invention, the cooling fan is mounted on the heat sink and the heat-generating component is mounted on the sub-circuit board separated from the main circuit board. And the thin design of the device housing is facilitated, and the advantageous effects that the cooling fan and the heat-generating component can be replaced simultaneously can be obtained.

[Brief description of the drawings]

FIG. 1 is a partial sectional view showing a heat dissipation structure of a portable computer according to an embodiment of the present invention.

FIG. 2 is a partial cross-sectional view showing a heat dissipation structure of a conventional portable computer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main circuit board 2 Sub-circuit board 3 CPU package 5 Cooling fan 6 Heat sink A 8 Heat sink B 9 Silicon sheet 10 Aluminum block

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroshi Tanio 1006 Kadoma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. 72) Inventor Kinji Sakurai 1006 Kazuma Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (3)

[Claims] A main circuit board on which an electronic component is mounted; a sub-circuit board on which an electronic component with heat generation, which is separated from the main circuit board and which is to be radiated (hereinafter, referred to as a heat generating component); An electronic device, comprising: a cooling fan for cooling the heat-generating component; and a heat sink to which the cooling fan is attached. 2. A cooling fan for cooling a heat-generating component,
A first heat sink to which the cooling fan is attached, a second heat sink that is in direct contact with the heat-generating component or through a heat-conductive material, and an opening formed in the heat-generating component mounting portion where the heat-generating component is mounted. And a heat conductive block interposed between the heat-generating component and the first heat sink through the opening. 3. A main circuit board on which electronic components are mounted, a sub circuit board separated from the main circuit board and on which a heat generating component is mounted, a cooling fan for cooling the heat generating component, and the cooling fan. A first heat sink to be attached, a second heat sink that is in close contact with the heat-generating component directly or through a heat conductive material, and a circuit board on which the heat-generating component is mounted and which has an opening in a mounting portion of the heat-generating component When,
An electronic device, comprising: a heat conductive block interposed between the heat generating component and the first heat sink through the opening.